The Internet includes multiple autonomous systems, each one using an interior gateway protocol to control routing within the autonomous system. Interior gateway protocols, such as OSPF (Open Shortest Path First) and DEFT (Distributed Exponentially-Weighted Flow spliTting), send flow through forward links towards a destination node. OSPF routes only on shortest-weight paths, whereas DEFT sends flow on all forward links, but with an exponential penalty on longer paths. Finding suitable weights for protocols such as these is known as the weight setting problem.